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Your search keyword '"Verdegaal, Andrew A."' showing total 14 results
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14 results on '"Verdegaal, Andrew A."'

3. Differential regulation of the Drosophila sleep homeostat by circadian and arousal inputs.

Author

Ni, Jinfei D, Gurav, Adishthi S, Liu, Weiwei, Ogunmowo, Tyler H, Hackbart, Hannah, Elsheikh, Ahmed, Verdegaal, Andrew A, and Montell, Craig

Subjects
Brain, Nerve Net, Animals, Drosophila, Arousal, Sleep, Circadian Rhythm, D. melanogaster, arousal, circadian rhythm, neuropeptides, neuroscience, sleep, Biochemistry and Cell Biology
Abstract

One output arm of the sleep homeostat in Drosophila appears to be a group of neurons with projections to the dorsal fan-shaped body (dFB neurons) of the central complex in the brain. However, neurons that regulate the sleep homeostat remain poorly understood. Using neurogenetic approaches combined with Ca2+ imaging, we characterized synaptic connections between dFB neurons and distinct sets of upstream sleep-regulatory neurons. One group of the sleep-promoting upstream neurons is a set of circadian pacemaker neurons that activates dFB neurons via direct glutaminergic excitatory synaptic connections. Opposing this population, a group of arousal-promoting neurons downregulates dFB axonal output with dopamine. Co-activating these two inputs leads to frequent shifts between sleep and wake states. We also show that dFB neurons release the neurotransmitter GABA and inhibit octopaminergic arousal neurons. We propose that dFB neurons integrate synaptic inputs from distinct sets of upstream sleep-promoting circadian clock neurons, and arousal neurons.

Published
2019

8. Structure and function of a 9.6 megadalton bacterial iron storage compartment: Supplementary Material

Author

Giessen, Tobias W., Orlando, Benjamin J., Verdegaal, Andrew A., Chambers, Melissa G., Gardener, Jules, Bell, David C., Birrane, Gabriel, Liao, Maofu, and Silver, Pamela A.

Abstract

Iron storage proteins are essential for maintaining intracellular iron homeostasis and redox balance. Iron is generally stored in a soluble and bioavailable form inside ferritin protein compartments. However, some organisms do not encode ferritins and thus rely on alternative storage strategies. Encapsulins, a class of protein-based organelles, have recently been implicated in microbial iron and redox metabolism. Here, we report the structural and mechanistic characterization of a 42 nm two-component encapsulin-based iron storage compartment from Quasibacillus thermotolerans . Using cryo-electron microscopy and x-ray crystallography, we reveal the assembly principles of a thermostable T = 4 shell topology and its catalytic ferroxidase cargo. We show that the cargo-loaded compartment has an exceptionally large iron storage capacity storing over 23,000 iron atoms. These results form the basis for understanding alternate microbial strategies for dealing with the essential element iron.

Published
2019
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